NEW YORK – It wasn’t a good night for the Nationals on Tuesday. Left-hander Mitchell Parker couldn’t get out of the fourth inning, and the offense was virtually nonexistent in a 10-1 loss to the Mets at Citi Field.

In Monday’s 2-1 loss to New York, the Nationals played as if they were in the Wild Card race until Starling Marte ended the game in the 10th with an RBI single. On Tuesday, Washington appeared finished by the third inning.

Parker is in his first full season in the big leagues, and there are going to be ups and downs. On this particular day, however, it was a downer. After Parker shut out New York during the first two innings, his outing suddenly went south in a four-run third.

One had to wonder if Parker was going to get out of that inning because the first five hitters he faced reached base. Pete Alonso highlighted the scoring with a two-run single. Parker was able to get out of the inning, but he left the game with two outs in the fourth and after throwing 78 pitches (45 strikes).

Parker didn’t make any excuses. He simply wasn’t executing his pitches.

“I was getting two strikes [on the hitter] and wasn’t able to put anything away,” Parker said. “You can’t really walk two guys and not expect anything bad to happen, especially against a team like the Mets.”

Said manager Dave Martinez: “He fell behind. He couldn’t get ahead, and then you have to pump strikes. The Mets can hit.”

Parker also needs to get better at fielding his position. In that third inning, with Luisangel Acuña on second, Jose Iglesias hit a shot to first baseman Joey Gallo, who dived for the ball and was set to throw to Parker at first. But Parker was nowhere to be found, and Gallo held the ball as Iglesias reached base with a single.

“It’s not really an excuse. I have to be over [at first base]. I have to get rid of the stutter step on the way over. Can’t let that happen,” Parker said.

Washington’s offense also struggled. The team was 0-for-5 with runners in scoring position.

The Nationals had Mets starter Tylor Megill on the ropes in the third inning, putting runners on first and third with no outs, but they could score only one run. James Wood hit into a fielder’s choice that allowed Jacob Young to score the only run of the game for Washington.

Four innings later and down by eight runs, the Nationals had the bases loaded with two outs against Adam Ottavino, but Wood struck out looking to end the threat.

“Our bats today, we couldn’t catch up to a fastball,” Martinez said. “[Megill] was throwing fastballs, and we were late. It was a bad combination. We could have had him early. It just didn’t happen. He had good movement on his fastball. When he is throwing a two-seamer like that, you can’t look to pull him. You have to stay on the ball. We were trying to pull the ball and late on fastballs.”